* Prices may differ from that shown
When people advertise old digital cameras on eBay, one of the things they know potential buyers will look for is that it comes bundled with a memory card. This is sensible enough, as most digicams have very small internal memories and some have none at all. However, a quick analysis of buying prices for such cameras seems to show that the capacity of the bundled card doesn't tend to make a big difference. Perhaps that's one reason why so many of the lower-spec models are sold together 16 MB cards, such as this xD example from Fujifilm.
There are any number of these cards around, since when the xD format was new (almost a decade ago now; the first cards were sold in 2002) the manufacturers tended to bundle one with their cameras. Given that two megapixels was a decent resolution back then, this wasn't entirely ridiculous - though it certainly was absurd when makers were still only providing 16 meg cards five years later! Fujifilm and Olympus were the companies involved in the xD standard, and the vast majority of xD cards bear one of those two names - even if they were actually made by the likes of Toshiba.
If you haven't previously been acquainted with an xD memory card, your first impression will be one of smallness. Really, only the micro-SD format that's become popular in recent years can match it for tininess. I'm not that keen on ultra-small cards of whatever format, which may be one reason that I've never much liked the xD version, but Fujifilm's 16-meg offering is no worse than anybody else's in that regard. It looks almost identical, too: the bright colours that differentiate one SD card from another are almost entirely absent from the xD world, and everything's really a bit dull and boring. (Memory cards often are, of course.)
The smallness of this card does mean that it's important that your camera has a sensible and straightforward mechanism for inserting and removing it, since if you drop the card in the undergrowth - or even long grass - you may never see it again! In general it follows the same push-in, push-out toggle arrangement as SD cards, and I've never had any problem with this thing in my venerable Fujifilm FinePix A203. You don't have to use Fujifilm cards in Fujifilm cameras, incidentally, and there seems no difference in performance when using an Olympus one instead. (In Olympus *cameras* it can make a difference, as there you'll need an Oly card to use panorama mode.)
16 megabytes is not a huge amount even for a two-megapixel camera like the A203. On its top resolution that model takes up about 700 kilobytes per photo, so a little bit of elementary arithmetic will tell you that you'll be able to store 22 or 23 such pictures on the card. Not even as much as on an old-fashioned 35 mm film! As for speed, well, the xD format (especially in this basic dress) has never been much of a speed demon, and you're not going to want to use it where lightning reactions are of the essence. If your camera supports the newer M or H types of xD card, then those are better bets all round.
The real problem with this card will reveal itself if and when you go looking for one to buy. The xD format is now obsolete, and though things haven't yet got as silly as they have for SmartMedia cards, prices are definitely going up. Perhaps surprisingly, even these low-capacity cards are in demand on eBay, and if you're not careful you can find yourself drawn into a bidding war (on a 16-meg card, gadzooks!) and paying a fiver - which is probably more than some of the cameras that use it! Given that 64- and even 256-meg cards are barely any more expensive, it's hard to recommend this 16 MB one. It works, yes, but so does a one-speed bicycle.